Hey guys, hoping someone can help me figure out what to try next. I have looked into the other posts and don't see anything with a post similar enough to mine to be any help.

A few weeks ago my AC blower motor stopped turning on. It had been replaced within the year with a part from Auto Zone. So I doubted that was the problem. I hooked up a voltage meeter to the blower motor plug and didn't get any voltage so I thought maybe it was the blower motor resistor.

I picked up a resistor from Auto Zone and connected it to the plug for the resistor and didn't have any luck with the blower starting. I didn't install the resistor in its spot since I didn't want to cut the old one out if it wasn't bad. Do you know if you have to install the resistor for it to work correctly?

So I took the resistor back and purchased a new voltage meter thinking my old one may have failed. Tried the new voltage meter on the blower motor plug and I am getting 12 volts there. So this made me think maybe the blower motor did fail. I picked up another motor from Auto Zone to see if it would work. I plugged in the new blower to the terminal and no luck, the fan didn't turn.

It is possible that the fan is dead out of the box, but I wanted to know what else I could test to see why the fan wasn't working.

If I have 12 volts at the blower motor terminal is that an indicator that everything else is working correctly? Thanks in advance!

 

Did you test the blower motor and resistors for resistance? That's where I'd start.

 

WitchingHour, any idea what the expected resistance is at the motor and resistor?

 

Run a hot wire directly from the battery to the blower motor. If the motor runs you know it is not the motor and if it does not you know that you need another motor.

 

I found the problem. The relay was bad. I didn't realize there was a relay in addition to the resistor. I pulled the relay off and saw one of the connections had fried. Quick trip to the store to swap the blower motor for a new relay and my fan works again.

Thanks for the tips.

 

Good deal. Glad you got it sorted out. As for the resistance, I'd have to look it up in my repair manual.

 

Hey guys. Thanks in advance for your help with this.

On my 97 blazer 4.3L my AC blower motor isn't getting power. For a while it was intermittent but now that the Summer heat is here in California it doesn't want to work at all. I have verified that the motor works by jumping a cable directly from the fan to the battery to see if it spins and it does.

I also was able to complete a circuit test on the purple wire that goes from the relay to the fan as well as the black wire from the relay to the fan so I don't think it is a wiring issue on that end at least.

The purple wire at the relay had gotten hot and melted the terminal connection and relay. I have cut out the original wiring connector and spliced in a new connector and replaced the relay.

I am not sure how to test the resistor. If I buy one and hook it up without cutting the old resistor out of the paneling to mount up the replacement should it work? Or does it need to be mounted to be grounded?

I fried my multimeter so I probably need to pick up a new one. Any tips on testing the resistor or other thoughts are welcome.

I looked around the site and there are a lot of helpful posts but I haven't had any luck still. And the post by Captain Hook here was helpful as well https://blazerforum.com/forum/2nd-ge...rk-high-78173/. There are so many posts that the original poster doesn't ever come back and write what the final solution was which is a pain.

 

* I have combined your threads on the same problem. Please keep it confined to a single thread so everybody can see what you have done to try to solve the issue. *

 

Just swapped the relay for a new one and purchased a resistor. Cut out the old resistor and installed the new one and hooked up the new relay but still no fan. This is driving me nuts.

Where should I look next?

 

Have you done a voltage check on the switch???